Slide-valve.



No. 643,467. Pateritod Feb. I3, I900. s. w. CARPENTER & n. WATSON.

SLIDE VALVE.

(Application filed Jime 20, 1899.) (No Model.) 2 Sheets-Sheet l.

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No. 643,467. Patented Fab. l3, I900. G. W. CARPENTER 81. R. WATSON.

SLIDE VALVE.

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PATENT SLIDE-VALVE.

SPECIFICATION forming part of Letters Patent No. 643,467, dated February 13, 1900.

- Application filed June 20, 1899. Serial No.721,240. (N model.)

To all whom it may concern..-

Be it known that we, GEORGE W. CARPEN- TER and ROBERT WATSON, of Nanaimo, British Columbia, Canada, have invented a new and useful Improvement in Slide-Valves, of which the following is a specification.

Our invention relates to improvements in slide-valves, and has for its object a simple device of this character which can be cheaply made and attached to any ordinary cylinder and which will act as an automatic drain for the cylinder to keep the same clear of condensed steam.

The invention consists in certain details of construction and combinations of the parts of the valves, which we shall first describe and then point out in the appended claims.

Reference is to be had to the accompanying drawings, forming part of this specification, in which like characters of reference indicate corresponding parts in all the views.

Figure 1 is a perspective view of our improved valves attached to a steam-cylinder. Fig. 2 is a vertical longitudinal section thereof. Fig. 3 is a detail view of the slide-valve cylinder detached. Fig. 4 is a similar view of the slide-valve piston. Fig. 5 is a section on the line 5 5, Fig. 6. Fig. 6 is a section end elevation taken on the line 6 6, Fig. 5; and Fig. 7 is a detail perspective View of the end of the slide-valve piston, the end of the connecting-rod, and a nut to hold said rod in place, all of said parts being shown detached.

The main steam-cylinder 10 is formed with the usual flanges ll, to which are secured by bolts or the like the covers 12 and 12 A stuffing-box or gland 13 is secured in the cover 12 and receives the piston-rod 14, carrying the piston 15.

The parts namedabove form no part of our present inventioh and may be of any pre: ferred construction, as our slide-valves are adaptable to any steam-cylinder of this general form.

In the bottom of the covers 12 and 12*, and preferably at the bottom of the same, are screwed or otherwise suitably secured the valve cylinders or barrels 16, open at both ends and one in each cover, and as they and their concomitant parts are alike in construction we shall describe but one. The barrel is formed with diametrically-opposite inlet and exhaust ports 17 and 18, respectively, around which the valve-cylinder is formed with screwthreaded nipples 19 and 20, adapted to receive the steam supply and exhaust pipes.

A piston 21, hollow for a portion of its length, is fitted to slide in the valve-cylinder 16 and is formed with inlet and exhaust ports 22 and 23, respectively, the said ports being diametrically opposite each other, but out of alinement and adapted to alternately register with the inlet and exhaust ports 17 and 18 of the valve-cylinder as the piston 21 is reciprocated therein. Piston-rings 24E surround the piston 21, one just in advance of the inlet-port 22 and the other at the commencement of the solid portion 25, which is just in rear of the exhaust-port 23. At its rear edge the piston 21 is provided with an annular flange 26, arranged to act as a stop for the inward movement of the piston, and a screwthreaded extension 27, formed with a noncircular base 28.

In order to reciprocate the pistons 21, we provide the connecting-rod 29, having its ends formed with apertures fitting upon the bases 28 of the extensions 27, being held thereon by nuts, and to guide the connecting-rod in its back-and-forth movement, whereby to prevent any rocking of the valves, we secure guide-rollers 30 on the main cylinder 10.

When the parts are in the position shown in Fig. 5, steam is entering the registering ports 17 and 22 of one valve and exhausting from the ports 18 and 23 of the other and the admitting piston is at the outward. limit of its movement, while the exhausting piston is at the inward limit of movement. It is to be understood that the pistons are considerably longer than their cylinders. Now as soon as the main piston 15 reaches the inwardly-projecting end of the exhausting piston it will proceed to push the latter outward,which will gradually close its exhaust and at the same time close the inlet-port of the admitting piston to the steam-supply. At one stage, then, it will be manifest both valves are entirely closed and the expansion of the steam in the main cylinder is utilized to further push the piston of one valve outward and to draw the piston of the other valve inward. Then immediately the registry of the ports commences to be reversed and the valve that had been ICO the admitting valve becomes the exhaustvalve, and vice versa, and the main piston is impelled in the opposite direction.

It is evident that by our improved arrangement the valve-pistons are instantly released from pressure at the end of the stroke of the main piston, while the piston just opening to the steam is assisted to its place by the steam and all unnecessary jar of the parts is avoided.

It is obvious that our improved valve can be attached to any ordinary steam-cylinder cover by merely tapping the latter and screwing the valve cylinder or barrel in place, and, if desired, they may be alternated by an eccentric attached to the connecting-bar by means of a connecting-rod. It will also be noted that by having the valve-cylinders located at the bottom of the covers 12 and by making the valve-pistons 2i hollow as far as their exhaust-ports the valves will allow condensed steam to flow readily out the exhaust, and thus act as an automatic drain to the main cylinder.

The rod 29 is provided with an aperture 31 to receive a reversing-lever.

Having thus described our invention, what we claim as new, and desire to secure by Letters Patent, is

1. The combination with a steam-cylinder, of the slide-valves, consisting of the oppositely-arranged open-ended valve-cylinders fitted in the cylinder-covers and provided with inlet and exhaust ports,the hollow valvepistons slidable in such cylinders and formed with inlet and exhaust ports arranged to alternately register with the ports in the cylinders, the said pistons being formed with annular flanges at their outer ends engaging with the outer ends of the valve-cylinders when the pistons are moved inward which latter are considerably larger than such cylinders whereby to project inside the main cylinder when slid inward, and means for reciprocating said pistons, as and for the purpose set forth.

2. The combination with a steam-cylinder, of the slide-valves consisting of the openended valve-cylinders fitted in the main cyl inder-covers and formed with diametrically opposite inlet and exhaust ports, the valvepistons slidable in said valve-cylinders and provided with the alternately-registering inlet and exhaust ports, the said pistons being provided with flanges at their rear ends whereby to stop their inward movement, and projecting within the main cylinder at the limit of such movement, an extension on the rear end of each valve-piston, and a connecting-rod having its ends held on said extensionswhereby to reciprocate the pistons, as set forth.

3. The herein'described slide-valve, comprising the open-ended cylinder, formed with inlet and exhaust ports and surrounding nipples and the hollow piston of greater length than said cylinder, being slidable therein and provided with alternately-registering ports, a flange on its rear end adapted to engage with the outer edge of the cylinder and a threaded extension on such rear end and formed with a non-circular base, as and for the purpose set forth.

GEORGE W. CARPENTER. ROBERT \VATSON. Witnesses:

C. H. BARKER, D. G. ALEXANDER. 

